Thieaudio Monarch MK3 default shell front over white background
Thieaudio Monarch MK3 default shell front 3 quarter and rear over white background
Thieaudio Monarch MK3 default shell front closeup on accessory case from Bloom Audio gallery
Thieaudio Monarch MK3 Sunset Horizon finish front over white background
Thieaudio Monarch MK3 Sunset Horizon finish front with stock cable over white background
Thieaudio Monarch MK3 Butterfly finish front over white background
Thieaudio Monarch MK3 Butterfly finish front with stock cable over white background
Thieaudio Monarch MK3 Disco finish front over white background
Thieaudio Monarch MK3 Disco finish front with stock cable over white background
Thieaudio Monarch MK3 Aurora Mix finish over white background
Thieaudio Monarch MK3 Aurora Mix finish with stock cable over white background
Thieaudio Monarch MK3 Aurora Crystal finish front over white background
Thieaudio Monarch MK3 Aurora Crystal finish front with stock cable over white background
ThieAudio Monarch MK3 Aurora Pink B2
ThieAudio Monarch MK3 Aurora Blue B3
ThieAudio Monarch MK3 Black Widow C2
ThieAudio Monarch MK3 Green Glamour C3
ThieAudio Monarch MK3 Blue Buoyant C4
ThieAudio Monarch MK3 Red Romance C5
ThieAudio Monarch MK3 Deep Dungeons D1
ThieAudio Monarch MK3 Sea Vines D2
ThieAudio Monarch MK3 Red Vivid D3
ThieAudio Monarch MK3 Green Urchin D4
Thieaudio Monarch MK3 all available shell colors and finishes chart

Thieaudio Monarch MKIII | Flagship Tribrid Universal IEMs

Regular price$999.00


Thieaudio logo

A Brilliantly Re-engineered Threequel: ThieAudio Enhances Their Tribrid Legend with the Monarch MKIII

  • 2 Dynamic drivers, 6 Balanced Armatures, and 2 Electrostatic drivers
  • Balanced Tonal Signature: The MKIII maintains a studio-monitor-esque tonal excellence while offering focused sub-bass impact
  • Enhanced Ultra-treble Output: now features Sonion's EST drivers and increased frequencies for improved staging and resolution
  • Improved Bass Quality: enjoy better quality bass without sacrificing tonal integrity with ThieAudio's IMPACT2 subwoofer innovation
  • Upgraded thicker 22AWG stock cable with modular plug design including 2.5mm, 3.5mm, and 4.4mm smart-switch plugs
  • (x6) shell colors with (x15) faceplate styles now available for a customizable finish

Bloom's Take

With the Monarch MK2, ThieAudio captured the highly resolving nature and micro-detail presentation of a flagship experience and delivered them with impressive value for the money. It was easily a best-seller IEM, earned a seat at the table of Bloom Audio's "Best Bang for your Buck" IEMs, and was rated as one of the best IEMs in the world by a number of reviewers and critics.

These are extremely big shoes to fill... but ThieAudio may have done just that with the Monarch MK3.

The MK3 successfully maintains a core tuning balance and delivers an elevated level of technical performance with excellent bass extension, natural and lifelike mids, and improved treble that provides sparkle and shimmer without sibilance and stabbing. Additionally, the imaging and soundstage are a clear standout.

The packaging and accessory kit for the MK3 remains essentially the same and is largely shared across ThieAudio’s lineup. However, the stock cable has changed and is more akin to the Oracle MKII cable. And while the new default faceplate is gorgeous, one of the big draws of the MK3 is the range of customizations available with the shells and faceplates offering about 80 possible combinations making this a special IEM.

Whether or not you love the changes from the MK2, the price, performance, and design make a really compelling case for Monarch MK3 as a near-flagship quality $1000 IEM that approaches "bass-head" territory.

Read our full review here.

ThieAudio Monarch MK2 and MK3 side-by-side with stock cables on wood tray from Bloom Audio gallery


IMPACT2 (“Impact Squared”) is ThieAudio's latest technological innovation to change the personalized audio industry. IMPACT2 is a new subwoofer solution consisting of (x2) 10mm composite diaphragm drivers arranged in an isobaric design. The addition of another 10mm subwoofer significantly enhances the power and texture of the bass, while the in-house isobaric chamber design keeps the frequency and pressure constant. This means you can enjoy better quality bass without sacrificing tonal integrity.

Enhanced Ultra-Treble Output

The Monarch MKIII has been updated with Sonion’s latest EST drivers and re-tuned to better exhibit their full potentials. Thanks to the new tuning strategy, the ultra-treble frequencies at +15kHz to 20kHz have been increased for a more comprehensive upper frequency extension. Compared to its predecessor, the Monarch MKIII will have a greater sense of staging, atmosphere, and an overall enhancement in perceived resolution thanks to this extension.

ThieAudio Monarch MK3 frequency response graph with Monarch MK2 comparison

Balanced Tonal Signature

At the core of the MKIII is a commitment to tonal excellence. It retains a studio-monitor like tonal signature with a focused sub-bass impact for a clean, natural, detailed sound. Engineered with a true 4-way crossover with 9 separate passive components, the Monarch MKIII stays true to its tonal legacy. Thanks to IMPACT2 , the subbass is punchier, but the mids from 200Hz to 800Hz retain their ruler-flat neutrality. This tonality of the mids mimics the true sound of studio monitors used in recording studios to deliver accurate audio reproduction.

Furthermore, the MKIII mids have been revamped to better separate respective driver ranges for maximum output while minimizing the THD. This means the mids will sound higher in resolution while retaining the same monitor-esque tonality. The treble has also been slightly re-tuned to offer more coherency throughout the region, as well as little more clarity and definition.

ThieAudio Monarch MK3 with attached stock cable on sea green folding pouch with plant from Bloom Audio gallery


  • Drivers: Sonion EST, Knowles DWFK 31785 (x2), Sonio 28UAP (x1), IMPACT2 (x2 10mm Composite DD)
  • Crossover: 4-Way Passive with 4 Sound Bores
  • Sensitivity: 99dB @ 1kHz (+/- 1dB)
  • Driver Impedance: 20Ω
  • Frequency Response: 20Hz-40kHz
  • Cable: 4' 22AWG 6N OCC Silver-plated and Graphene Silver-plated
  • Termination: 2-pin 0.78mm with (x3) modular Smart-switch (2.5mm, 3.5mm, 4.4mm)

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Customer Reviews

Based on 16 reviews
Douglas Ropel
No regrets

I was skeptical that these (or any) headphones/IEMs could sound good enough to justify this kind of $$$. These definitely ended that skepticism. Love ‘em.

Arian Fuentes
Good at the everything

Amazing for all my music and all my gaming couldn’t complain and way better for then my previous iem best defult tuning out there by a land slide the one and done for 90% of ppl.

Christopher Montiel
Awesome Seller, Awesome Product

First off, the packaging blew me away! Bloom Audio melted my heart with their careful packaging and the adorable little chocolate bar they place neatly in a little ziplock with a sticker. Just heartwarming! The product was in perfect brand new condition and the IEMS are best-in-class of any tribrid I've ever used. Thanks Bloom Audio for being so wholesome and excellent in service, never change 🥹!

Jamie Larson
Absolutely love it!

This was my first try at an IEM, and I picked it because the MKII was so critically acclaimed, and I decided to purchase the "upgraded" version. I was a little worried about the sound signature being too "neutral" but the MKIII sounds quite warm to my ears, which I actually prefer. I almost exclusively listen to music using these now over my headphones. Can't recommend it enough as an IEM!

Isaac G.
Endgame All-rounder!

First off, before I start talking about the IEM I just want to say Bloom Audio absolutely was a pleasure to purchase from & talk to. Every question was answered promptly and kindly. There was a issue that occurred with my order on their end that was promptly and professionally taken care of!!

Now, as for the Monarch...

A truly amazing set! It fixed the (minor) issues I had with my Monarch MKII in the way of the shell ergonomics could be improved & I wanted a little extra bass as on some tracks, my MKII was *just* passable I found.

The MKIII fixed that and then some. Adding more bass, improved treble, & improving upon the shell itself by making it more ergonomic (also recessed 2 pin connections finally!) and a better fit than the MKII was for me, even though it was far from being uncomfortable.

In terms of music, so far everything that I've thrown at the MKIII has sounded excellent. And I listen to a little bit of everything honestly. Though my most popular genres are rock / altrock, grunge, Pop, soul, blues & r&b. From Jeff Buckley, SRV, AiC, to thefatrat all sounded excellent.

So now, the Thieaudio Monarch MKIII takes up the spot in my collection as my personal "Endgame" set. It also helps that my custom design that yes, I had to wait for, exceeded my expectations and is a total stunner! (blue on blue shell/ faceplate!)
Thanks again to Bloom Audio for being an absolute pleasure to purchase from & and even bigger thanks to Thieaudio for listening to feedback on the Monarch MKII and making another banger with the new Monarch MKIII

You may also like

Recently viewed